This is a randomized, multi-center,phase III study to evaluate the ability of thalidomide maintenance therapy to prolong relapse-free survival in diffuse large B cell lymphoma(DLBCL).

This is a randomized, phase III study to evaluate the ability of thalidomide maintenance therapy to prolong relapse-free survival(RFS), in diffuse large B cell lymphoma(DLBCL).Patients will be enrolled after successful standard induction therapy (CR or CRu following standard R-CHOP-like therapy with 8 infusions of rituximab plus CHOP-like chemotherapy (4-8 cycles). Patients will be followed until an event occurs as defined in the protocol. To evaluate the clinical efficacy of thalidomide maintenance therapy as compared to observation in patients with DLBCL who have achieved a complete remission after appropriate first-line therapy, measured by RFS, 226 patients with DLCBL will be recruited.

Inclusion Criteria:

• NCCN-IPI>1,
• Known IPI, cell of origin and DHL at time of diagnosis,
• Negative pregnancy test,
• Men must agree not to father a child during the therapy,
• 6 to 8 cycles R-CHOP/like, total of 8 x Rituximab,
• CR, CRu

Exclusion Criteria:

• Transformed lymphoma,
• Secondary malignancy,
• HIV positive,
• Evidence of CNS involvement,
• Cardiac dysfunction (systolic ejection fraction <50%),
• Creatinine > 2.0 mg/dl